British media attacks on EU product policies did much to put a golden energy efficiency policy area on ice. Now the Brits are sailing away, is the coast clear for Europe to ramp up ambition? The answer depends on how the European institutions respond to the unfolding ‘Brexistential’ crisis and the rise of populism. Embracing a deregulation agenda may be instinctive, to do less of what can hurt, but this is a kind of mini-Brexit in its own right, walking away from the argument. A better solution would be to better justify to voters how and why these sensible policies exist.